Improvement in expanding-mandrels



n. P Kane. I E x-panding 'Mandre'ls.

Patented July 21,1874

H! O IIT n e V n J Fig. 2

UNITED STATES PATENT O FICE.

nanny P. KING, or BENHAMS P. 0.,INDIANA.

IMPROVEMENT IN EXPANDlNG-MANDRELS.

Specification forming part of Letters Patent No. 153,347, dated July 21,1874; application filed June 22, 1874.

To all whom it may concern Be it known that I, HENRY P. KING, of BenhamsPost Office, Ripley county, State of Indiana, have invented a certainnew and use ful Improvement in Expanding-Mandrels, of

which the following is a specification:

My invention relates to the class of machinists mandrels adapted to fitvarious sizes of circular openin gs or bores in work to be turned, themandrel serving to hold the work tightly while being turned; and myinvention consists of a combination of split sleeve, expansible to fitbores of different sizes, a conical plug to fit the same interiorly, anda central mandrel, having screw-threads, washers, and nuts upon it, tosupport and operate the diiferent parts of the mandrel, the constructionof the mandrel being such that it is adapted to receive different sizesof conical plugs and expansible sleeves, so as to render one centralmandrel adapted to be used with a great range of bores in the work to beheld.

Figure 1 is a perspective view of my improved eXpanding-mandrel. Fig. 2is an axial section of the same.

A is the stem or central shaft of the mandrel, which is properlycentered, as shown at a, to rest between centers of laths, and isprovided with screw-threads b 0 upon it, one of which, I), isleft-handed, and used to support the conical plug B, a number of whichare provided of different sizes, to interchange for different sizes ofwork. The other screw, 0, is provided with a nut, G, to operate a loosecollar, D, which is used to force the expanding-sleeve E over theconical plug, so as to increase the diameter of the expanding-sleeve tofit the Work to be held. The work is held upon the exterior of thisexpanding-sleeve E, and if necessary the sleeve may be in sections ofdifferent diameters exteriorly, to fit various sizes of bores withoutexpansion necessarily. A permanent nut or head, F, is provided on thecentral mandrel A, against which the conical plug B is firmly screwed,the left-hand screw preventing, in the usual rotation of the lathe, anydisplacement of the plug.

In the operation of the mandrel, the work to be turned or otherwiseoperated upon is placed over the expansible sleeve, and the nut O isscrewed up, so as to cause the collar D to force the conically-boredsleeve E over the conical plug B, and thus the sleeve is expanded toclosely fit the work to be held.

I claim The combination of double threaded mandrel A b c, plug B,expanding-sleeve E, loose washer D, and tightening-nut (J, connected andoperating substantially as and for the purpose specified.

In testimony of which invention I hereunto set my hand.

HENRY P. KING. Vitnesses EDGAR J. Gnoss, J. L. W ARTMANN.

